Category General Spine Peter F. Duggan, MD Anshu Shukla, MD Akshita Mehta Rosalyn A. Jurjus, MD, PhD Raymond Tu, MD, FACR Purpose Head and neck radiologists are very familiar with compartmental anatomy of the neck, although all lumbar spine and abdominal/pelvic imaging studies include the paraspinal soft tissues, the anatomy and conditions of this region are less understood . We will review the paraspinal soft tissue anatomy of the lumbosacral region with emphasis of the fascial spaces using gross anatomic and imaging correlation with CT and MRI. Materials & Methods LEARNING POINTS: Participants will be expected to come away from the session with an understanding of the following concepts: 1. Anatomy of the paraspinal soft tissues of the lumbrosacral spine. 2. Unique features of the fascial compartments of the paraspinal soft tissues. 3. Differential diagnosis of neurological, neoplastic and inflammatory conditions related to each compartment with gross anatomic with CT and MRI correlation. 4. Origin, insertion, innervation, vascular supply, principal function each lumbar paraspinal muscle. Results LEARNING POINTS: Participants will be expected to come away from the session with an understanding of the following concepts: 1. Anatomy of the paraspinal soft tissues of the lumbrosacral spine. 2. Unique features of the fascial compartments of the paraspinal soft tissues. 3. Differential diagnosis of neurological, neoplastic and inflammatory conditions related to each compartment with gross anatomic with CT and MRI correlation. 4. Origin, insertion, innervation, vascular supply, principal function each lumbar paraspinal muscle. Conclusion LEARNING POINTS: Participants will be expected to come away from the session with an understanding of the following concepts: 1. Anatomy of the paraspinal soft tissues of the lumbrosacral spine. 2. Unique features of the fascial compartments of the paraspinal soft tissues. 3. Differential diagnosis of neurological, neoplastic and inflammatory conditions related to each compartment with gross anatomic with CT and MRI correlation. 4. Origin, insertion, innervation, vascular supply, principal function each lumbar paraspinal muscle. References LEARNING POINTS: Participants will be expected to come away from the session with an understanding of the following concepts: 1. Anatomy of the paraspinal soft tissues of the lumbrosacral spine. 2. Unique features of the fascial compartments of the paraspinal soft tissues. 3. Differential diagnosis of neurological, neoplastic and inflammatory conditions related to each compartment with gross anatomic with CT and MRI correlation. 4. Origin, insertion, innervation, vascular supply, principal function each lumbar paraspinal muscle.